Adjustable bridge for stringed instruments



May 28, 1957 P. STIPETIC ADJUSTABLE BRIDGE FOR STRINGED INSTRUMENTS Filed July 23, 1954 FIG.

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a H mw 1 Mw/ WmWm 5\/.W M M. 2 2 J K 4 J a N r w G A r 2 F a f o a 3 United States Patent ADJUSTABLE BRIDGE FOR STRINGED INSTRUMENTS Paul Stipetic, Campbell, Ohio, assignor of fifty percent to George Stipetic, Campbell, Ohio Application July 23, 1954, Serial No. 445,251

4 Claims. (Cl. 84-307) This invention relates to stringed instruments in general and more particularly to an adjustable bridge therefor wherein individual string rests are provided which may be adjusted to vary the effective position of the rest.

The principal object of the invention is the provision of a bridge for a stringed instrument incorporating individual adjustable string rests.

A further object of the invention is the provision of a bridge for a stringed instrument wherein individual string rests and individually actuated means for adjusting the position of the individual string rests are provided.

A still further object of the invention is the provision of a bridge for a stringed instrument incorporating a plurality of individually adjustable string rests and adjustment means for adjusting and holding the individual string rests in desired position.

Those skilled in the art will recognize that bridges incorporating adjustable string rests have heretofore been proposed and that such adjustable bridges have generally been difficult to adjust and incapable of maintaining a desired adjustment.

The present disclosure relates to an adjustable bridge incorporating individual string rests which may be individually adjusted and which will, by reason of the construction of the adjusting mechanism retain their adjusted position as long as desired.

It is well known that in order to achieve proper tuning of a stringed instrument, such as a mandolin or a guitar, it is often desirable that a string rest be moved longitudinally with respect to the particular string with which it is assembled and that once the proper position of the string rest with respect to the string is obtained, the adjustment be permanently held.

The device disclosed herein makes possible such proper tuning of the stringed instrument and secures the individual string rests in the proper adjusted position and thereby holding the same in desired relation to the strings.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being the intention to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a top plan view of a stringed instrument showing the adjustable bridge in position thereon.

Figure 2 is an enlarged top plan view of the adjustable bridge.

Figure 3 is an enlarged detailed cross sectional elevation taken on line 33 of Figure 2.

Figure 4 is an enlarged cross sectional elevation taken on line 4-4 of Figure 2.

By referring to the drawings and Figure l in particular it will be seen that a stringed instrument has been dis- 2,793,557 Patented May 28, 1957 closed and is generally indicated by the numeral 10. A plurality of strings S are positioned on the stringed instrument 10 in the usual manner and they are supported by an adjustable bridge, generally indicated by the numer-al 11.

By referring now to Figures 2, 3 and 4 of the drawings it will be seen that the adjustable bridge comprises the main body member 11, the upper surface of which is formed with a plurality of transversely extending slots 12-12 therein which terminate inwardly from one side of the body member 11 and extend through the opposite side, as best seen in Figure 4 of the drawings.

A closure plate 13 is positioned on the body member 11 and secured thereto by a pair of fasteners l414. The closure plate 13 incorporates a plurality of slots 1515 which register with the slots 12-12 in the body member, as heretofore described. Each of the slots 15 serves to mount an individual string rest 16 which cornprises a principal string rest portion mounted in a U-shaped bracket 17 and secured thereto by a transverse shaft 18. The U-shaped bracket 17 is provided with 21 depending lug 19 having a threaded aperture 20 positioned transversely thereof so that a threaded shaft 21 may be engaged therein.

It will thus be seen that rotation of the threaded shaft 21 will cause the string rest 16 to move longitudinally of the slots 12 and 15 and hence provide the desired degree of adjustment for properly tuning the string carried on the respective string rest.

In order that the threaded shaft 21 can be revolved easily and accurately, one end thereof is provided with spaced collars 22 so that a snap ring 23 can be positioned therebetween and secure the shaft in position with respect to a downturned flange 24 on the plate 13 and a downturned flange 25 which forms a part of a bracket 26 secured on one side thereof and extending longitudinally of the body member 11.

The outermost end of the shaft 21 beyond the collars 22 is provided with a bifurcated end 27 which is engaged upon a dual pivot member 28, the other portions of which are engaged in a bifurcated end 29 of a squared shaft extension 30 which extends through and outwardly of the bracket 26 and at an inclination from horizontal and an inclination from the longitudinal center line of the threaded shaft 21.

Those skilled in the art will observe that the bifurcated ends 27 and 29 and the dual pivot member 28 comprise an effective universal joint by means of which rotating motion imparted to the squared shaft extensions 30 as by means of a suitable key (not shown) is conveyed to the threaded shaft 21 which will then move the individual string rests 16 in order to effect a desired adjustment.

The squared shaft 30 is provided with a collar 31 and a snap ring 32 is positioned between the collar 31 and the outer face of the bracket 26 to mount the assembly in rotatable but otherwise fixed relation to the bracket 26.

It will thus be seen that each of the individual string rests 16 is provided with an individual acting means comprising the threaded shafts 21 and the squared shafts 30 which extend outwardly through the brackets 26. It will also be seen that the ends of the squared shafts 30 are offset with respect to the longitudinal positioning of the strings 30 and that they can therefore be readily engaged with a suitable key for the necessary adjustment.

It will also be observed by those skilled in the art that the threaded shafts 21 engaging the threaded apertures 20 in the depending lug 19, which are portions of the individual string rests 16, securely position the individual string rests 16 in desired position on the threaded shafts 21 and thus secure the same against accidental movement and thereby achieve one of the principal objects of the invention.

It will thus be seen that the several objects of the in- I rests positioned one in each of said U-shaped brackets,

said depending lugs having threaded apertures therein, a plurality of threaded shafts rotatably mounted in said closure plate and engaging said threaded apertures in said depending lugs and means for rotating said threaded shafts whereby said string rests are moved lengthwise of said slots.

2. The adjustable bridge for stringed instruments set forth in claim 1 and wherein said closure plate has a sidewardly extending L-shaped flange and wherein said threaded shafts are journaled in said L-shaped flange.

3. The adjustable bridge for stringed instruments set forth in claim 1 and wherein said closure plate has a depending flange along one side thereof and an outwardly and downwardly extending flange adjacent thereto and wherein said threaded shafts are journaled in said depending fiange and wherein secondary shafts having squared end extensions are journaled in said outwardly and downwardly depending flange and universally movable connections join said shafts.

4. An adjustable bridge for stringed instruments and comprising a hollow body member adapted to be mounted on said instrument, a closure plate extending across the upper surface of said hollow body member and downwardly along one side thereof, a plurality of transversely extending slots in said closure plate and a string rest movably mounted in each of said slots, a depending lug formed on each of said string rests, said depending lug having a threaded aperture therein, a plurality of threaded shafts journaled in said closure plate and positioned transversely in said hollow body member and beneath the slots in said closure plate and engaged in said threaded apertures in said depending lugs, an angular flange on said closure plate anda plurality of secondary shafts journaled in said angular flange and motion transmitting means interconnecting said secondary shafts and said first mentioned threaded shafts.

References Cited in the file of this patent UNITED STATES PATENTS 383,275 Bowers May 2, 1888 1,595,798 Marino Aug. 10, 1926 1,724,278 Grover Aug. 13, 1929 

